The present invention generally pertains to apparatus for injection molding of plastic products and is particularly directed to an injection molding apparatus for high pressure injection molding of thermoplastic materials which reduces counteractive deformation of a first molding cavity, the deformation occurring when desynchronously filling a second molding cavity which is coaxially positioned in relation to the first cavity.
It is believed that the problem of counteractive deformation of a first unfilled molding cavity, when desynchronously filling a second molding cavity has heretofore not been described.
Prior art description of desynchronously injected molding is shown in the following Hagerborg, U.S. Pat. Nos. 3,049,757 Teraoka, 3,417,433 Lohmann, 3,707,342 Bishop, 4,005,964 Balevski, 4,090,837 Tsuchiya, 4,242,073 Elly et al., 4,153,405 Sorensen, 4,400,341 Sorensen 4,464,327 and Sorensen 4,539,171.